I have a two part question. I have a customer that has a variable primary flow system with two air cooled chillers. They have had control issues with the flow fluctuations caused by the opening of isolation valves during the transition from one chiller to two chillers. This is a common problem with VPF systems. I have corrected the issue via slowing down the isolation valve cycle times but based upon the literature out there another possible solution is placing their chillers in series. So this is where I get to my question(s).
1) What is the best way to model variable primary flow in OpenStudio, and: 2) Can you model two chillers in series and to VPF?
